Primary structural studies will be carried out on tubulin dimers from sea urchin and molluscan ciliary and flagellar outer doublet and central pair microtubules in order to compare these proteins to one another and to the tubulin dimers from cytoplasmic microtubules and to relate any differences to the biological function of specific microtubules. Thin-layer peptide mapping, amino acid composition, and sequence determination will be performed on tryptic fragments of tubulin subunits derived from preparative polyacrylamide gel electrophoresis. In addition, protein synthetic studies will be carried out during ciliary growth in sea urchin embryos in order to determine how temporal synthesis relates to the spatial assembly of the orgenelle. Specific protein synthesis will be evaluated by autoradiographic analysis of electrophoretically-resolved ciliary protein fractions. Emphasis will be placed on the minor "architectural" proteins and their possible role in microtubule assembly and "9+2" geometry. BIBLIOGRAPHIC REFERENCES: Stephens, R. E., and Edds, K.T., "Microtubules: Structure, Chemistry, and Function," Physiological Reviews 56: 709-777, 1976. Pratt, M.M., and Stephens, R.E., "Evidence for a Cytoplasmic Dynein," Biophys. J. 17: 268a, 1977 (Abstract).